- Patent Title: White light source and white light source system including the same
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Application No.: US14356275Application Date: 2012-10-19
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Publication No.: US09605815B2Publication Date: 2017-03-28
- Inventor: Masahiko Yamakawa , Yasuhiro Shirakawa
- Applicant: KABUSHIKI KAISHA TOSHIBA , TOSHIBA MATERIALS CO., LTD.
- Applicant Address: JP Tokyo JP Yokohama-Shi
- Assignee: KABUSHIKI KAISHA TOSHIBA,TOSHIBA MATERIALS CO., LTD.
- Current Assignee: KABUSHIKI KAISHA TOSHIBA,TOSHIBA MATERIALS CO., LTD.
- Current Assignee Address: JP Tokyo JP Yokohama-Shi
- Agency: Foley & Lardner LLP
- Priority: JP2011-243992 20111107
- International Application: PCT/JP2012/077087 WO 20121019
- International Announcement: WO2013/069435 WO 20130516
- Main IPC: F21V3/04
- IPC: F21V3/04 ; H01L33/50 ; F21V9/16 ; F21K99/00 ; F21K9/232 ; F21K9/64 ; H01L25/075 ; F21Y101/00

Abstract:
The present invention provides a white light source comprising a light emitting diode having a light emission peak wavelength of 350 to 490 nm and a phosphor that emits visible light upon excitation by a light emitted from the light emitting diode; wherein, with respect to an arbitrary local maximum value of light-emission intensity between 350 and 780 nm of a light emission spectrum of the white light source, a ratio of a local minimum value of light-emission intensity that is closest on a long wavelength side to the local maximum value is such that, when the local maximum value is taken as 1, the local minimum value is 0.5 or more. It is preferable that, with respect to an arbitrary local maximum value of light-emission intensity between 350 and 780 nm of a light emission spectrum of the white light source, a ratio of a local minimum value of light-emission intensity that is closest on a long wavelength side to the local maximum value is such that, when the local maximum value is taken as 1, the local minimum value is 0.7 or more. According to the above structure, there can be provided a white light source capable of preventing a specified wavelength region from protruding in the light emission spectrum, and capable of visually perceiving the color tone of the irradiation object as the same state where the object is irradiated with sunlight.
Public/Granted literature
- US20140307417A1 WHITE LIGHT SOURCE AND WHITE LIGHT SOURCE SYSTEM INCLUDING THE SAME Public/Granted day:2014-10-16
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